A roller tappet may be used as a component assembly of a high-pressure pump to transfer a force to a pump piston of a high-pressure pump. Due to the application of force, the pump piston moves and can reduce the volume of a pump working area of the high-pressure pump, for example. When fuel is fed to the pump working area via an inlet valve during a downwards movement of the pump piston, the pump piston compresses the fuel within the pump working area during the upwards movement due to the reduction in volume of the pump working area.
The roller tappet usually has a tappet which bears against the pump piston and transfers a force onto said pump piston. Furthermore, the roller tappet has a roller which is coupled with the tappet and, when the high-pressure pump is used in a fuel injection system, runs on a running surface of a cam of a drive shaft. The roller tappet enables the rotatory movement of the drive shaft to be converted into a translatory movement of the tappet and therefore of the pump piston, so that the pump piston is moved in an axial direction.
When a medium, for example a fuel, is compressed in the pump working area, a high force of up to a ton, for example, acts on the pump piston. The piston force is also transferred onto the roller tappet and therefore both to the tappet and also the roller. In order to avoid damage during pump operation, the roller should bear against the surface of the cam with its bearing surface in a full-faced manner. However, this is only fulfilled when the piston force transferred by the pump piston onto the roller tappet is evenly transferred to the roller tappet and therefore the tappet and the roller.